We are in the process of upgrading my uncles motor from a flat tappet cam to a solid roller.He has a set of 3/8 stud roller rockers and no stud girdle.The spring I am looking at putting in it are K-Motion K-800 which have 165Lbs on the seatand 471 Lbs with the valve open with the cam we are going to run.I am thinking we may be ok just adding a stud girdle to his current setup.The motor will be under 7,000 rpm.Thanks in advance for advice...

* If the cam only needs those spring pressures you can probably get by with 3/8" studs (if they are screw in like Ken said), with a stud girdle on it.

* I assume he wants to save money by not buying new rockers and studs, but I would never buy 3/8" to begin with.

* With the information given there is no way to know (or even speculate) the amount of spring pressure needed.

* In my friend's 355 I did a spring check to find most springs as low as 175# and some as low as 160. We changed to new 210-220# springs and it didn't pick up at all. Cam was Herbert 268/275 .650ish lift with 1.6 rockers shifted at 7200. Most people are running excess spring IMO, just to be safe.

Jody that is probably the best thing to do. I have broken 3/8 with a stud girdle with a 519/523 cam. Then went to 7/16 ARP and a gidle and don't even think about it. I have a new set of Harland sharp 1.7's for a big block. Only 20 minutes on them.

Well scored some comp cams 7/16 Stud Girdles today in great shape for $50Also a set of 7/16 Rockers for $60 I think they are Lunati's but not 100% sure.Also looks like we have a set of studs already. So that is a real cheap upgrade!

Just for grins my 23˚ 427 has 3/8" studs and stud girdles, never an issue over 7500 with K-900 springs and a 285/295@.050 cam. Intake lift just over .700 with 1.6 rockers. At the time I put it together I had the rockers and could not afford the change, but never an issue with them.